The present invention generally relates to sensors and detection systems. More particularly, this invention relates to a system and method thereof which alerts users of a changing environment based on the rate of change of a parameter being sensed, regardless of the actual level of that parameter.
Personal gas monitors are gas detection instruments used to identify the presence of a gas or vapor in an environment. These monitors are generally portable and carried by users to warn them of hazardous gases as the users work in environments that may contain unknown amounts of hazardous gases, for example, if the user was investigating and/or repairing a gas leak. Personal gas monitors have a variety of applications for use with fire and emergency service personnel, confined space entry, utilities, water treatment plants, mining, steel mills, police, hazmat, shipping, transportation, telecom, refineries, offshore drilling platforms, petrochemical plants, parking garages, pharmaceuticals, manufacturing, HVAC, laboratories and any industries where accidental leakage of gas or vapors can endanger workers.
Gas monitors have sensors that detect the presence and level of a gas in a surrounding environment, and, if a level of the gas exceeds a level, typically indicated as a percentage of the entire environment predetermined to be hazardous to a human, the gas monitor alerts the user, for example, with an audible and/or visible alarm. However, currently available personal gas monitors may be limited as they can only provide a warning to the user once the level of the gas in the environment reaches the predetermined level. Therefore, the user may be exposed to hazardous gases that are at levels below prescribed levels, yet may still be hazardous to the user based on the duration of the exposure or the physical condition of the user, or that may later be determined to be hazardous. Furthermore, the user may remain unaware of a rapid increase in the level of a gas in the environment, reducing the user's ability to escape prior to the environment becoming dangerous.
In view of the above, there is a need for a system which can alert users of a potentially dangerous environment prior to the environment reaching levels deemed dangerous by conventional monitors and standards.